Frequently Asked Questions

Frequently Asked Questions


1. What is the World Meteorological Organization?

The World Meteorological Organization (WMO) is a specialized agency of the United Nations dedicated to meteorology (weather), climatology (climate), operational hydrology (water) and other related geophysical sciences such as oceanography and atmospheric chemistry.

2. When did WMO start?

WMO originates from the International Meteorological Organization (IMO), which dates back to 1873. The WMO mandate, constituent bodies and procedures are set out in the WMO Convention, which entered into force on 23 March 1950 – a year later WMO became a specialized agency of the United Nations.

3. What does WMO do?

WMO coordinates the activities of National Meteorological and Hydrological Services in 193 States and Territories so that basic weather, climate and water services are made available to anyone who needs them, when they need them. 

Through this coordination, a global, end-to-end capability that delivers worldwide access to a wide variety of real-time and non-real-time data and information was established in 1950 and has since undergone continuous improvement in scope, reliability and accuracy. These weather, climate and water services contribute towards socio-economic development, environmental management and policy formulation. 

WMO guarantees the publication of observations and statistics and furthers the application of meteorology and hydrology (including the monitoring and predictions of climate change and ozone) to all aspects of human activities such as aviation, shipping, water management and agriculture. WMO also encourages research and training in meteorology and hydrology and their related applications and contributes towards reducing the impact of weather- and climate-related hazards. This is accomplished through regular, reliable forecasts and early warnings on flooding, drought, tropical cyclones, tornadoes and other extreme events. 

Predictions concerning locust swarms and the transport of pollutants (nuclear and toxic substances, volcanic ash) are also provided by WMO Members.

4. How does WMO function?

WMO acts as a central framework where Members, including representatives of National Meteorological and Hydrology Services (NMHSs), can effectively discuss all issues related to weather, climate and water. The goal of WMO is to ensure that these streams of information flow as rapidly and efficiently as possible and contribute to the safety and well-being of all peoples. 

The WMO is governed by the World Meteorological Congress, which is composed of all WMO Members. The World Meteorological Congress meets every four years to review, and give policy guidance to, WMO Programmes. The Executive Council (37 members), which meets annually, monitors the implementation of decisions taken by Congress. Members gather in regional associations (RAs: Asia, Africa, Europe; North America, Central America and the Caribbean; South America and South-West Pacific) to coordinate activities within their respective Regions. Members select experts to take part in eight technical commissions researching issues within their areas of competence. 

The Secretary-General heads the Secretariat, which is based in Geneva. The Secretariat acts as an administration, documentation and information centre for the Organization. Pressing issues or international emergencies that need to be addressed can be accommodated through existing programmes.

5. How does WMO monitor global weather and climate?

WMO undertakes this task through the National Meteorological and Hydrological Services of its Members, which own and operate the systems for collecting, processing and analysing information from thousands of observation systems, including satellites and ships.

WMO issues Annual, Five-Year and Decadal Statements on the Status of the Global Climate. These statements document extreme weather and climate events in the regional context and provide a historical perspective on the variability and trends of climate, particularly surface temperatures that have occurred since the 19th century. WMO also works with National Meteorological and Hydrological Services to develop climate change detection tools and software to compute indices that reflect the best estimate of climate trends within the countries.

6. What is the difference between weather and climate?

Climate, in a narrow sense, can be defined as the average weather conditions for a particular location and period of time. In a wider sense, it is the state of the climate system. Climate can be described in terms of statistical descriptions of the central tendencies and variability of relevant elements such as temperature, precipitation, atmospheric pressure, humidity and winds or through combinations of elements, such as weather types and phenomena that are typical to a location, region or the world for any period of time.

7. How many states are Members of WMO?

The WMO Membership comprises 187 states and 6 territories.

8. What are WMO Member Territories?

Both states and territories may become WMO Members. Member Territories include: Any territory or group of territories maintaining its own Meteorological Service and listed in Annex II of WMO Basic Documents No. 1 (page 25 ); any territory or group of territories maintaining its own Meteorological Service that is not listed in Annex II  but which is not responsible for the conduct of its international relations; or any trust territory or group of trust territories maintaining its own Meteorological Service and administered by the United Nations.

Find out more in the WMO Basics Document (No. 1).

9. How do Members interact?

Delegates and experts work together on various programmes, exchanging information, research, statistics and technology to provide a better picture of global conditions. They also share experiences and discuss ways of discovering and employing improvements.